profile-generator.cc 37.9 KB
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// Copyright 2012 the V8 project authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
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#include "src/profiler/profile-generator.h"
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#include <algorithm>

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#include "include/v8-profiler.h"
#include "src/base/lazy-instance.h"
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#include "src/codegen/source-position.h"
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#include "src/objects/shared-function-info-inl.h"
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#include "src/profiler/cpu-profiler.h"
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#include "src/profiler/profile-generator-inl.h"
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#include "src/profiler/profiler-stats.h"
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#include "src/tracing/trace-event.h"
#include "src/tracing/traced-value.h"
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namespace v8 {
namespace internal {

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void SourcePositionTable::SetPosition(int pc_offset, int line,
                                      int inlining_id) {
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  DCHECK_GE(pc_offset, 0);
  DCHECK_GT(line, 0);  // The 1-based number of the source line.
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  // It's possible that we map multiple source positions to a pc_offset in
  // optimized code. Usually these map to the same line, so there is no
  // difference here as we only store line number and not line/col in the form
  // of a script offset. Ignore any subsequent sets to the same offset.
  if (!pc_offsets_to_lines_.empty() &&
      pc_offsets_to_lines_.back().pc_offset == pc_offset) {
    return;
  }
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  // Check that we are inserting in ascending order, so that the vector remains
  // sorted.
  DCHECK(pc_offsets_to_lines_.empty() ||
         pc_offsets_to_lines_.back().pc_offset < pc_offset);
  if (pc_offsets_to_lines_.empty() ||
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      pc_offsets_to_lines_.back().line_number != line ||
      pc_offsets_to_lines_.back().inlining_id != inlining_id) {
    pc_offsets_to_lines_.push_back({pc_offset, line, inlining_id});
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  }
}

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int SourcePositionTable::GetSourceLineNumber(int pc_offset) const {
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  if (pc_offsets_to_lines_.empty()) {
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    return v8::CpuProfileNode::kNoLineNumberInfo;
  }
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  auto it = std::lower_bound(
      pc_offsets_to_lines_.begin(), pc_offsets_to_lines_.end(),
      SourcePositionTuple{pc_offset, 0, SourcePosition::kNotInlined});
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  if (it != pc_offsets_to_lines_.begin()) --it;
  return it->line_number;
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}

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int SourcePositionTable::GetInliningId(int pc_offset) const {
  if (pc_offsets_to_lines_.empty()) {
    return SourcePosition::kNotInlined;
  }
  auto it = std::lower_bound(
      pc_offsets_to_lines_.begin(), pc_offsets_to_lines_.end(),
      SourcePositionTuple{pc_offset, 0, SourcePosition::kNotInlined});
  if (it != pc_offsets_to_lines_.begin()) --it;
  return it->inlining_id;
}

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size_t SourcePositionTable::Size() const {
  return sizeof(*this) + pc_offsets_to_lines_.capacity() *
                             sizeof(decltype(pc_offsets_to_lines_)::value_type);
}

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void SourcePositionTable::print() const {
  base::OS::Print(" - source position table at %p\n", this);
  for (const SourcePositionTuple& pos_info : pc_offsets_to_lines_) {
    base::OS::Print("    %d --> line_number: %d inlining_id: %d\n",
                    pos_info.pc_offset, pos_info.line_number,
                    pos_info.inlining_id);
  }
}

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const char* const CodeEntry::kEmptyResourceName = "";
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const char* const CodeEntry::kEmptyBailoutReason = "";
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const char* const CodeEntry::kNoDeoptReason = "";
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const char* const CodeEntry::kProgramEntryName = "(program)";
const char* const CodeEntry::kIdleEntryName = "(idle)";
const char* const CodeEntry::kGarbageCollectorEntryName = "(garbage collector)";
const char* const CodeEntry::kUnresolvedFunctionName = "(unresolved function)";
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const char* const CodeEntry::kRootEntryName = "(root)";
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// static
CodeEntry* CodeEntry::program_entry() {
  static base::LeakyObject<CodeEntry> kProgramEntry(
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      LogEventListener::FUNCTION_TAG, CodeEntry::kProgramEntryName,
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      CodeEntry::kEmptyResourceName, v8::CpuProfileNode::kNoLineNumberInfo,
      v8::CpuProfileNode::kNoColumnNumberInfo, nullptr, false,
      CodeEntry::CodeType::OTHER);
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  return kProgramEntry.get();
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}

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// static
CodeEntry* CodeEntry::idle_entry() {
  static base::LeakyObject<CodeEntry> kIdleEntry(
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      LogEventListener::FUNCTION_TAG, CodeEntry::kIdleEntryName,
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      CodeEntry::kEmptyResourceName, v8::CpuProfileNode::kNoLineNumberInfo,
      v8::CpuProfileNode::kNoColumnNumberInfo, nullptr, false,
      CodeEntry::CodeType::OTHER);
  return kIdleEntry.get();
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}

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// static
CodeEntry* CodeEntry::gc_entry() {
  static base::LeakyObject<CodeEntry> kGcEntry(
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      LogEventListener::BUILTIN_TAG, CodeEntry::kGarbageCollectorEntryName,
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      CodeEntry::kEmptyResourceName, v8::CpuProfileNode::kNoLineNumberInfo,
      v8::CpuProfileNode::kNoColumnNumberInfo, nullptr, false,
      CodeEntry::CodeType::OTHER);
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  return kGcEntry.get();
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}

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// static
CodeEntry* CodeEntry::unresolved_entry() {
  static base::LeakyObject<CodeEntry> kUnresolvedEntry(
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      LogEventListener::FUNCTION_TAG, CodeEntry::kUnresolvedFunctionName,
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      CodeEntry::kEmptyResourceName, v8::CpuProfileNode::kNoLineNumberInfo,
      v8::CpuProfileNode::kNoColumnNumberInfo, nullptr, false,
      CodeEntry::CodeType::OTHER);
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  return kUnresolvedEntry.get();
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}

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// static
CodeEntry* CodeEntry::root_entry() {
  static base::LeakyObject<CodeEntry> kRootEntry(
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      LogEventListener::FUNCTION_TAG, CodeEntry::kRootEntryName,
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      CodeEntry::kEmptyResourceName, v8::CpuProfileNode::kNoLineNumberInfo,
      v8::CpuProfileNode::kNoColumnNumberInfo, nullptr, false,
      CodeEntry::CodeType::OTHER);
  return kRootEntry.get();
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}

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uint32_t CodeEntry::GetHash() const {
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  uint32_t hash = 0;
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  if (script_id_ != v8::UnboundScript::kNoScriptId) {
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    hash ^= ComputeUnseededHash(static_cast<uint32_t>(script_id_));
    hash ^= ComputeUnseededHash(static_cast<uint32_t>(position_));
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  } else {
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    hash ^= ComputeUnseededHash(
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        static_cast<uint32_t>(reinterpret_cast<uintptr_t>(name_)));
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    hash ^= ComputeUnseededHash(
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        static_cast<uint32_t>(reinterpret_cast<uintptr_t>(resource_name_)));
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    hash ^= ComputeUnseededHash(line_number_);
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  }
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  return hash;
}

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bool CodeEntry::IsSameFunctionAs(const CodeEntry* entry) const {
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  if (this == entry) return true;
  if (script_id_ != v8::UnboundScript::kNoScriptId) {
    return script_id_ == entry->script_id_ && position_ == entry->position_;
  }
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  return name_ == entry->name_ && resource_name_ == entry->resource_name_ &&
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         line_number_ == entry->line_number_;
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}

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void CodeEntry::SetBuiltinId(Builtin id) {
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  bit_field_ = TagField::update(bit_field_, LogEventListener::BUILTIN_TAG);
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  bit_field_ = BuiltinField::update(bit_field_, id);
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}

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int CodeEntry::GetSourceLine(int pc_offset) const {
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  if (line_info_) return line_info_->GetSourceLineNumber(pc_offset);
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  return v8::CpuProfileNode::kNoLineNumberInfo;
}

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void CodeEntry::SetInlineStacks(
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    std::unordered_set<CodeEntry*, Hasher, Equals> inline_entries,
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    std::unordered_map<int, std::vector<CodeEntryAndLineNumber>>
        inline_stacks) {
  EnsureRareData()->inline_entries_ = std::move(inline_entries);
  rare_data_->inline_stacks_ = std::move(inline_stacks);
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}

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const std::vector<CodeEntryAndLineNumber>* CodeEntry::GetInlineStack(
    int pc_offset) const {
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  if (!line_info_) return nullptr;

  int inlining_id = line_info_->GetInliningId(pc_offset);
  if (inlining_id == SourcePosition::kNotInlined) return nullptr;
  DCHECK(rare_data_);

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  auto it = rare_data_->inline_stacks_.find(inlining_id);
  return it != rare_data_->inline_stacks_.end() ? &it->second : nullptr;
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}
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void CodeEntry::set_deopt_info(
    const char* deopt_reason, int deopt_id,
    std::vector<CpuProfileDeoptFrame> inlined_frames) {
  RareData* rare_data = EnsureRareData();
  rare_data->deopt_reason_ = deopt_reason;
  rare_data->deopt_id_ = deopt_id;
  rare_data->deopt_inlined_frames_ = std::move(inlined_frames);
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}

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void CodeEntry::FillFunctionInfo(SharedFunctionInfo shared) {
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  if (!shared.script().IsScript()) return;
  Script script = Script::cast(shared.script());
  set_script_id(script.id());
  set_position(shared.StartPosition());
  if (shared.optimization_disabled()) {
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    set_bailout_reason(GetBailoutReason(shared.disabled_optimization_reason()));
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  }
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}

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size_t CodeEntry::EstimatedSize() const {
  size_t estimated_size = 0;
  if (rare_data_) {
    estimated_size += sizeof(rare_data_.get());

    for (const auto& inline_entry : rare_data_->inline_entries_) {
      estimated_size += inline_entry->EstimatedSize();
    }
    estimated_size += rare_data_->inline_entries_.size() *
                      sizeof(decltype(rare_data_->inline_entries_)::value_type);

    for (const auto& inline_stack_pair : rare_data_->inline_stacks_) {
      estimated_size += inline_stack_pair.second.size() *
                        sizeof(decltype(inline_stack_pair.second)::value_type);
    }
    estimated_size +=
        rare_data_->inline_stacks_.size() *
        (sizeof(decltype(rare_data_->inline_stacks_)::key_type) +
         sizeof(decltype(rare_data_->inline_stacks_)::value_type));

    estimated_size +=
        rare_data_->deopt_inlined_frames_.capacity() *
        sizeof(decltype(rare_data_->deopt_inlined_frames_)::value_type);
  }

  if (line_info_) {
    estimated_size += line_info_.get()->Size();
  }
  return sizeof(*this) + estimated_size;
}

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CpuProfileDeoptInfo CodeEntry::GetDeoptInfo() {
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  DCHECK(has_deopt_info());

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  CpuProfileDeoptInfo info;
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  info.deopt_reason = rare_data_->deopt_reason_;
  DCHECK_NE(kNoDeoptimizationId, rare_data_->deopt_id_);
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  if (rare_data_->deopt_inlined_frames_.empty()) {
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    info.stack.push_back(CpuProfileDeoptFrame(
        {script_id_, static_cast<size_t>(std::max(0, position()))}));
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  } else {
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    info.stack = rare_data_->deopt_inlined_frames_;
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  }
  return info;
}

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CodeEntry::RareData* CodeEntry::EnsureRareData() {
  if (!rare_data_) {
    rare_data_.reset(new RareData());
  }
  return rare_data_.get();
}
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void CodeEntry::ReleaseStrings(StringsStorage& strings) {
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  DCHECK_EQ(ref_count_, 0UL);

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  if (name_) {
    strings.Release(name_);
    name_ = nullptr;
  }
  if (resource_name_) {
    strings.Release(resource_name_);
    resource_name_ = nullptr;
  }
}

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void CodeEntry::print() const {
  base::OS::Print("CodeEntry: at %p\n", this);

  base::OS::Print(" - name: %s\n", name_);
  base::OS::Print(" - resource_name: %s\n", resource_name_);
  base::OS::Print(" - line_number: %d\n", line_number_);
  base::OS::Print(" - column_number: %d\n", column_number_);
  base::OS::Print(" - script_id: %d\n", script_id_);
  base::OS::Print(" - position: %d\n", position_);

  if (line_info_) {
    line_info_->print();
  }

  if (rare_data_) {
    base::OS::Print(" - deopt_reason: %s\n", rare_data_->deopt_reason_);
    base::OS::Print(" - bailout_reason: %s\n", rare_data_->bailout_reason_);
    base::OS::Print(" - deopt_id: %d\n", rare_data_->deopt_id_);

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    if (!rare_data_->inline_stacks_.empty()) {
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      base::OS::Print(" - inline stacks:\n");
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      for (auto it = rare_data_->inline_stacks_.begin();
           it != rare_data_->inline_stacks_.end(); it++) {
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        base::OS::Print("    inlining_id: [%d]\n", it->first);
        for (const auto& e : it->second) {
          base::OS::Print("     %s --> %d\n", e.code_entry->name(),
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                          e.line_number);
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        }
      }
    } else {
      base::OS::Print(" - inline stacks: (empty)\n");
    }

    if (!rare_data_->deopt_inlined_frames_.empty()) {
      base::OS::Print(" - deopt inlined frames:\n");
      for (const CpuProfileDeoptFrame& frame :
           rare_data_->deopt_inlined_frames_) {
        base::OS::Print("script_id: %d position: %zu\n", frame.script_id,
                        frame.position);
      }
    } else {
      base::OS::Print(" - deopt inlined frames: (empty)\n");
    }
  }
  base::OS::Print("\n");
}

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ProfileNode::~ProfileNode() {
  if (tree_->code_entries()) tree_->code_entries()->DecRef(entry_);
}

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CpuProfileNode::SourceType ProfileNode::source_type() const {
  // Handle metadata and VM state code entry types.
  if (entry_ == CodeEntry::program_entry() ||
      entry_ == CodeEntry::idle_entry() || entry_ == CodeEntry::gc_entry() ||
      entry_ == CodeEntry::root_entry()) {
    return CpuProfileNode::kInternal;
  }
  if (entry_ == CodeEntry::unresolved_entry())
    return CpuProfileNode::kUnresolved;

  // Otherwise, resolve based on logger tag.
  switch (entry_->tag()) {
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    case LogEventListener::EVAL_TAG:
    case LogEventListener::SCRIPT_TAG:
    case LogEventListener::LAZY_COMPILE_TAG:
    case LogEventListener::FUNCTION_TAG:
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      return CpuProfileNode::kScript;
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    case LogEventListener::BUILTIN_TAG:
    case LogEventListener::HANDLER_TAG:
    case LogEventListener::BYTECODE_HANDLER_TAG:
    case LogEventListener::NATIVE_FUNCTION_TAG:
    case LogEventListener::NATIVE_SCRIPT_TAG:
    case LogEventListener::NATIVE_LAZY_COMPILE_TAG:
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      return CpuProfileNode::kBuiltin;
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    case LogEventListener::CALLBACK_TAG:
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      return CpuProfileNode::kCallback;
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    case LogEventListener::REG_EXP_TAG:
    case LogEventListener::STUB_TAG:
    case LogEventListener::CODE_CREATION_EVENT:
    case LogEventListener::CODE_DISABLE_OPT_EVENT:
    case LogEventListener::CODE_MOVE_EVENT:
    case LogEventListener::CODE_DELETE_EVENT:
    case LogEventListener::CODE_MOVING_GC:
    case LogEventListener::SHARED_FUNC_MOVE_EVENT:
    case LogEventListener::SNAPSHOT_CODE_NAME_EVENT:
    case LogEventListener::TICK_EVENT:
    case LogEventListener::NUMBER_OF_LOG_EVENTS:
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      return CpuProfileNode::kInternal;
  }
}

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void ProfileNode::CollectDeoptInfo(CodeEntry* entry) {
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  deopt_infos_.push_back(entry->GetDeoptInfo());
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  entry->clear_deopt_info();
}

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ProfileNode* ProfileNode::FindChild(CodeEntry* entry, int line_number) {
  auto map_entry = children_.find({entry, line_number});
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  return map_entry != children_.end() ? map_entry->second : nullptr;
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}

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ProfileNode* ProfileNode::FindOrAddChild(CodeEntry* entry, int line_number) {
  auto map_entry = children_.find({entry, line_number});
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  if (map_entry == children_.end()) {
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    ProfileNode* node = new ProfileNode(tree_, entry, this, line_number);
    children_[{entry, line_number}] = node;
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    children_list_.push_back(node);
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    return node;
  } else {
    return map_entry->second;
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  }
}


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void ProfileNode::IncrementLineTicks(int src_line) {
  if (src_line == v8::CpuProfileNode::kNoLineNumberInfo) return;
  // Increment a hit counter of a certain source line.
  // Add a new source line if not found.
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  auto map_entry = line_ticks_.find(src_line);
  if (map_entry == line_ticks_.end()) {
    line_ticks_[src_line] = 1;
  } else {
    line_ticks_[src_line]++;
  }
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}


bool ProfileNode::GetLineTicks(v8::CpuProfileNode::LineTick* entries,
                               unsigned int length) const {
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  if (entries == nullptr || length == 0) return false;
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  unsigned line_count = static_cast<unsigned>(line_ticks_.size());
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  if (line_count == 0) return true;
  if (length < line_count) return false;

  v8::CpuProfileNode::LineTick* entry = entries;

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  for (auto p = line_ticks_.begin(); p != line_ticks_.end(); p++, entry++) {
    entry->line = p->first;
    entry->hit_count = p->second;
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  }

  return true;
}

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void ProfileNode::Print(int indent) const {
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  int line_number = line_number_ != 0 ? line_number_ : entry_->line_number();
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  base::OS::Print("%5u %*s %s:%d %d %d #%d", self_ticks_, indent, "",
                  entry_->name(), line_number, source_type(),
                  entry_->script_id(), id());
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  if (entry_->resource_name()[0] != '\0')
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    base::OS::Print(" %s:%d", entry_->resource_name(), entry_->line_number());
  base::OS::Print("\n");
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  for (const CpuProfileDeoptInfo& info : deopt_infos_) {
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    base::OS::Print(
        "%*s;;; deopted at script_id: %d position: %zu with reason '%s'.\n",
        indent + 10, "", info.stack[0].script_id, info.stack[0].position,
        info.deopt_reason);
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    for (size_t index = 1; index < info.stack.size(); ++index) {
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      base::OS::Print("%*s;;;     Inline point: script_id %d position: %zu.\n",
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                      indent + 10, "", info.stack[index].script_id,
                      info.stack[index].position);
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    }
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  }
  const char* bailout_reason = entry_->bailout_reason();
  if (bailout_reason != GetBailoutReason(BailoutReason::kNoReason) &&
      bailout_reason != CodeEntry::kEmptyBailoutReason) {
    base::OS::Print("%*s bailed out due to '%s'\n", indent + 10, "",
                    bailout_reason);
  }
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  for (auto child : children_) {
    child.second->Print(indent + 2);
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  }
}

class DeleteNodesCallback {
 public:
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  void BeforeTraversingChild(ProfileNode*, ProfileNode*) { }

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  void AfterAllChildrenTraversed(ProfileNode* node) { delete node; }
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  void AfterChildTraversed(ProfileNode*, ProfileNode*) { }
};

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ProfileTree::ProfileTree(Isolate* isolate, CodeEntryStorage* storage)
    : next_node_id_(1),
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      isolate_(isolate),
      code_entries_(storage),
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      root_(new ProfileNode(this, CodeEntry::root_entry(), nullptr)) {}
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ProfileTree::~ProfileTree() {
  DeleteNodesCallback cb;
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  TraverseDepthFirst(&cb);
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}

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ProfileNode* ProfileTree::AddPathFromEnd(const std::vector<CodeEntry*>& path,
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                                         int src_line, bool update_stats) {
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  ProfileNode* node = root_;
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  CodeEntry* last_entry = nullptr;
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  for (auto it = path.rbegin(); it != path.rend(); ++it) {
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    if (*it == nullptr) continue;
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    last_entry = *it;
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    node = node->FindOrAddChild(*it, v8::CpuProfileNode::kNoLineNumberInfo);
  }
  if (last_entry && last_entry->has_deopt_info()) {
    node->CollectDeoptInfo(last_entry);
  }
  if (update_stats) {
    node->IncrementSelfTicks();
    if (src_line != v8::CpuProfileNode::kNoLineNumberInfo) {
      node->IncrementLineTicks(src_line);
    }
  }
  return node;
}

ProfileNode* ProfileTree::AddPathFromEnd(const ProfileStackTrace& path,
                                         int src_line, bool update_stats,
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                                         ProfilingMode mode) {
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  ProfileNode* node = root_;
  CodeEntry* last_entry = nullptr;
  int parent_line_number = v8::CpuProfileNode::kNoLineNumberInfo;
  for (auto it = path.rbegin(); it != path.rend(); ++it) {
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    if (it->code_entry == nullptr) continue;
    last_entry = it->code_entry;
    node = node->FindOrAddChild(it->code_entry, parent_line_number);
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    parent_line_number = mode == ProfilingMode::kCallerLineNumbers
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                             ? it->line_number
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                             : v8::CpuProfileNode::kNoLineNumberInfo;
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  }
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  if (last_entry && last_entry->has_deopt_info()) {
    node->CollectDeoptInfo(last_entry);
  }
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  if (update_stats) {
    node->IncrementSelfTicks();
    if (src_line != v8::CpuProfileNode::kNoLineNumberInfo) {
      node->IncrementLineTicks(src_line);
    }
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  }
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  return node;
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}

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class Position {
 public:
  explicit Position(ProfileNode* node)
      : node(node), child_idx_(0) { }
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  V8_INLINE ProfileNode* current_child() {
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    return node->children()->at(child_idx_);
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  }
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  V8_INLINE bool has_current_child() {
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    return child_idx_ < static_cast<int>(node->children()->size());
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  }
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  V8_INLINE void next_child() { ++child_idx_; }
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  ProfileNode* node;
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 private:
  int child_idx_;
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};


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// Non-recursive implementation of a depth-first post-order tree traversal.
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template <typename Callback>
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void ProfileTree::TraverseDepthFirst(Callback* callback) {
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  std::vector<Position> stack;
  stack.emplace_back(root_);
  while (stack.size() > 0) {
    Position& current = stack.back();
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    if (current.has_current_child()) {
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      callback->BeforeTraversingChild(current.node, current.current_child());
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      stack.emplace_back(current.current_child());
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    } else {
      callback->AfterAllChildrenTraversed(current.node);
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      if (stack.size() > 1) {
        Position& parent = stack[stack.size() - 2];
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        callback->AfterChildTraversed(parent.node, current.node);
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        parent.next_child();
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      }
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      // Remove child from the stack.
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      stack.pop_back();
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    }
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  }
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}

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void ContextFilter::OnMoveEvent(Address from_address, Address to_address) {
  if (native_context_address() != from_address) return;

  set_native_context_address(to_address);
}

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using v8::tracing::TracedValue;

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CpuProfile::CpuProfile(CpuProfiler* profiler, ProfilerId id, const char* title,
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                       CpuProfilingOptions options,
                       std::unique_ptr<DiscardedSamplesDelegate> delegate)
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    : title_(title),
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      options_(options),
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      delegate_(std::move(delegate)),
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      start_time_(base::TimeTicks::Now()),
580
      top_down_(profiler->isolate(), profiler->code_entries()),
581
      profiler_(profiler),
582
      streaming_next_sample_(0),
583
      id_(id) {
584 585 586 587 588 589 590 591 592
  // The startTime timestamp is not converted to Perfetto's clock domain and
  // will get out of sync with other timestamps Perfetto knows about, including
  // the automatic trace event "ts" timestamp. startTime is included for
  // backward compatibility with the tracing protocol but the value of "ts"
  // should be used instead (it is recorded nearly immediately after).
  auto value = TracedValue::Create();
  value->SetDouble("startTime", start_time_.since_origin().InMicroseconds());
  TRACE_EVENT_SAMPLE_WITH_ID1(TRACE_DISABLED_BY_DEFAULT("v8.cpu_profiler"),
                              "Profile", id_, "data", std::move(value));
593 594

  DisallowHeapAllocation no_gc;
595 596 597
  if (delegate_) {
    delegate_->SetId(id_);
  }
598 599 600 601 602
  if (options_.has_filter_context()) {
    i::Address raw_filter_context =
        reinterpret_cast<i::Address>(options_.raw_filter_context());
    context_filter_.set_native_context_address(raw_filter_context);
  }
603
}
604

605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621
bool CpuProfile::CheckSubsample(base::TimeDelta source_sampling_interval) {
  DCHECK_GE(source_sampling_interval, base::TimeDelta());

  // If the sampling source's sampling interval is 0, record as many samples
  // are possible irrespective of the profile's sampling interval. Manually
  // taken samples (via CollectSample) fall into this case as well.
  if (source_sampling_interval.IsZero()) return true;

  next_sample_delta_ -= source_sampling_interval;
  if (next_sample_delta_ <= base::TimeDelta()) {
    next_sample_delta_ =
        base::TimeDelta::FromMicroseconds(options_.sampling_interval_us());
    return true;
  }
  return false;
}

622
void CpuProfile::AddPath(base::TimeTicks timestamp,
623
                         const ProfileStackTrace& path, int src_line,
624 625 626
                         bool update_stats, base::TimeDelta sampling_interval,
                         StateTag state_tag,
                         EmbedderStateTag embedder_state_tag) {
627 628
  if (!CheckSubsample(sampling_interval)) return;

629 630
  ProfileNode* top_frame_node =
      top_down_.AddPathFromEnd(path, src_line, update_stats, options_.mode());
631

632
  bool should_record_sample =
633
      !timestamp.IsNull() && timestamp >= start_time_ &&
634 635
      (options_.max_samples() == CpuProfilingOptions::kNoSampleLimit ||
       samples_.size() < options_.max_samples());
636

637
  if (should_record_sample) {
638 639
    samples_.push_back(
        {top_frame_node, timestamp, src_line, state_tag, embedder_state_tag});
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  }

  if (!should_record_sample && delegate_ != nullptr) {
    const auto task_runner = V8::GetCurrentPlatform()->GetForegroundTaskRunner(
        reinterpret_cast<v8::Isolate*>(profiler_->isolate()));

    task_runner->PostTask(std::make_unique<CpuProfileMaxSamplesCallbackTask>(
        std::move(delegate_)));
    // std::move ensures that the delegate_ will be null on the next sample,
    // so we don't post a task multiple times.
  }
651

652 653
  const int kSamplesFlushCount = 100;
  const int kNodesFlushCount = 10;
654
  if (samples_.size() - streaming_next_sample_ >= kSamplesFlushCount ||
655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675
      top_down_.pending_nodes_count() >= kNodesFlushCount) {
    StreamPendingTraceEvents();
  }
}

namespace {

void BuildNodeValue(const ProfileNode* node, TracedValue* value) {
  const CodeEntry* entry = node->entry();
  value->BeginDictionary("callFrame");
  value->SetString("functionName", entry->name());
  if (*entry->resource_name()) {
    value->SetString("url", entry->resource_name());
  }
  value->SetInteger("scriptId", entry->script_id());
  if (entry->line_number()) {
    value->SetInteger("lineNumber", entry->line_number() - 1);
  }
  if (entry->column_number()) {
    value->SetInteger("columnNumber", entry->column_number() - 1);
  }
676
  value->SetString("codeType", entry->code_type_string());
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  value->EndDictionary();
  value->SetInteger("id", node->id());
  if (node->parent()) {
    value->SetInteger("parent", node->parent()->id());
  }
  const char* deopt_reason = entry->bailout_reason();
  if (deopt_reason && deopt_reason[0] && strcmp(deopt_reason, "no reason")) {
    value->SetString("deoptReason", deopt_reason);
  }
}

}  // namespace

void CpuProfile::StreamPendingTraceEvents() {
  std::vector<const ProfileNode*> pending_nodes = top_down_.TakePendingNodes();
692
  if (pending_nodes.empty() && samples_.empty()) return;
693 694
  auto value = TracedValue::Create();

695
  if (!pending_nodes.empty() || streaming_next_sample_ != samples_.size()) {
696 697 698 699 700 701 702 703 704
    value->BeginDictionary("cpuProfile");
    if (!pending_nodes.empty()) {
      value->BeginArray("nodes");
      for (auto node : pending_nodes) {
        value->BeginDictionary();
        BuildNodeValue(node, value.get());
        value->EndDictionary();
      }
      value->EndArray();
705
    }
706
    if (streaming_next_sample_ != samples_.size()) {
707
      value->BeginArray("samples");
708
      for (size_t i = streaming_next_sample_; i < samples_.size(); ++i) {
709
        value->AppendInteger(samples_[i].node->id());
710 711 712 713
      }
      value->EndArray();
    }
    value->EndDictionary();
714
  }
715
  if (streaming_next_sample_ != samples_.size()) {
716 717 718 719 720 721 722 723 724 725
    // timeDeltas are computed within CLOCK_MONOTONIC. However, trace event
    // "ts" timestamps are converted to CLOCK_BOOTTIME by Perfetto. To get
    // absolute timestamps in CLOCK_BOOTTIME from timeDeltas, add them to
    // the "ts" timestamp from the initial "Profile" trace event sent by
    // CpuProfile::CpuProfile().
    //
    // Note that if the system is suspended and resumed while samples_ is
    // captured, timeDeltas derived after resume will not be convertible to
    // correct CLOCK_BOOTTIME time values (for instance, producing
    // CLOCK_BOOTTIME time values in the middle of the suspended period).
726 727
    value->BeginArray("timeDeltas");
    base::TimeTicks lastTimestamp =
728
        streaming_next_sample_ ? samples_[streaming_next_sample_ - 1].timestamp
729
                               : start_time();
730 731 732 733
    for (size_t i = streaming_next_sample_; i < samples_.size(); ++i) {
      value->AppendInteger(static_cast<int>(
          (samples_[i].timestamp - lastTimestamp).InMicroseconds()));
      lastTimestamp = samples_[i].timestamp;
734 735
    }
    value->EndArray();
736 737 738 739 740 741 742 743 744 745
    bool has_non_zero_lines =
        std::any_of(samples_.begin() + streaming_next_sample_, samples_.end(),
                    [](const SampleInfo& sample) { return sample.line != 0; });
    if (has_non_zero_lines) {
      value->BeginArray("lines");
      for (size_t i = streaming_next_sample_; i < samples_.size(); ++i) {
        value->AppendInteger(samples_[i].line);
      }
      value->EndArray();
    }
746
    streaming_next_sample_ = samples_.size();
747 748 749
  }

  TRACE_EVENT_SAMPLE_WITH_ID1(TRACE_DISABLED_BY_DEFAULT("v8.cpu_profiler"),
750
                              "ProfileChunk", id_, "data", std::move(value));
751 752
}

753
void CpuProfile::FinishProfile() {
754
  end_time_ = base::TimeTicks::Now();
755 756
  // Stop tracking context movements after profiling stops.
  context_filter_.set_native_context_address(kNullAddress);
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  StreamPendingTraceEvents();
  auto value = TracedValue::Create();
  // The endTime timestamp is not converted to Perfetto's clock domain and will
  // get out of sync with other timestamps Perfetto knows about, including the
  // automatic trace event "ts" timestamp. endTime is included for backward
  // compatibility with the tracing protocol: its presence in "data" is used by
  // devtools to identify the last ProfileChunk but the value of "ts" should be
  // used instead (it is recorded nearly immediately after).
  value->SetDouble("endTime", end_time_.since_origin().InMicroseconds());
  TRACE_EVENT_SAMPLE_WITH_ID1(TRACE_DISABLED_BY_DEFAULT("v8.cpu_profiler"),
                              "ProfileChunk", id_, "data", std::move(value));
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}

770
void CpuProfile::Print() const {
771
  base::OS::Print("[Top down]:\n");
772
  top_down_.Print();
773 774
  ProfilerStats::Instance()->Print();
  ProfilerStats::Instance()->Clear();
775 776
}

777 778 779 780 781 782
void CodeEntryStorage::AddRef(CodeEntry* entry) {
  if (entry->is_ref_counted()) entry->AddRef();
}

void CodeEntryStorage::DecRef(CodeEntry* entry) {
  if (entry->is_ref_counted() && entry->DecRef() == 0) {
783 784 785 786 787
    if (entry->rare_data_) {
      for (auto* inline_entry : entry->rare_data_->inline_entries_) {
        DecRef(inline_entry);
      }
    }
788 789 790 791 792 793
    entry->ReleaseStrings(function_and_resource_names_);
    delete entry;
  }
}

CodeMap::CodeMap(CodeEntryStorage& storage) : code_entries_(storage) {}
794

795 796 797
CodeMap::~CodeMap() { Clear(); }

void CodeMap::Clear() {
798 799
  for (auto& slot : code_map_) {
    if (CodeEntry* entry = slot.second.entry) {
800
      code_entries_.DecRef(entry);
801 802 803
    } else {
      // We expect all entries in the code mapping to contain a CodeEntry.
      UNREACHABLE();
804 805
    }
  }
806 807

  code_map_.clear();
808
}
809

810
void CodeMap::AddCode(Address addr, CodeEntry* entry, unsigned size) {
811
  code_map_.emplace(addr, CodeEntryMapInfo{entry, size});
812 813 814 815 816 817 818
  entry->set_instruction_start(addr);
}

bool CodeMap::RemoveCode(CodeEntry* entry) {
  auto range = code_map_.equal_range(entry->instruction_start());
  for (auto i = range.first; i != range.second; ++i) {
    if (i->second.entry == entry) {
819
      code_entries_.DecRef(entry);
820 821 822 823 824
      code_map_.erase(i);
      return true;
    }
  }
  return false;
825 826
}

827
void CodeMap::ClearCodesInRange(Address start, Address end) {
828 829 830 831
  auto left = code_map_.upper_bound(start);
  if (left != code_map_.begin()) {
    --left;
    if (left->first + left->second.size <= start) ++left;
832
  }
833
  auto right = left;
834
  for (; right != code_map_.end() && right->first < end; ++right) {
835
    code_entries_.DecRef(right->second.entry);
836
  }
837
  code_map_.erase(left, right);
838 839
}

840
CodeEntry* CodeMap::FindEntry(Address addr, Address* out_instruction_start) {
841 842 843
  // Note that an address may correspond to multiple CodeEntry objects. An
  // arbitrary selection is made (as per multimap spec) in the event of a
  // collision.
844 845 846
  auto it = code_map_.upper_bound(addr);
  if (it == code_map_.begin()) return nullptr;
  --it;
847 848
  Address start_address = it->first;
  Address end_address = start_address + it->second.size;
849
  CodeEntry* ret = addr < end_address ? it->second.entry : nullptr;
850 851
  DCHECK(!ret || (addr >= start_address && addr < end_address));
  if (ret && out_instruction_start) *out_instruction_start = start_address;
852
  return ret;
853 854
}

855 856
void CodeMap::MoveCode(Address from, Address to) {
  if (from == to) return;
857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875

  auto range = code_map_.equal_range(from);
  // Instead of iterating until |range.second|, iterate the number of elements.
  // This is because the |range.second| may no longer be the element past the
  // end of the equal elements range after insertions.
  size_t distance = std::distance(range.first, range.second);
  auto it = range.first;
  while (distance--) {
    CodeEntryMapInfo& info = it->second;
    DCHECK(info.entry);
    DCHECK_EQ(info.entry->instruction_start(), from);
    info.entry->set_instruction_start(to);

    DCHECK(from + info.size <= to || to + info.size <= from);
    code_map_.emplace(to, info);
    it++;
  }

  code_map_.erase(range.first, it);
876 877
}

878
void CodeMap::Print() {
879
  for (const auto& pair : code_map_) {
880
    base::OS::Print("%p %5d %s\n", reinterpret_cast<void*>(pair.first),
881
                    pair.second.size, pair.second.entry->name());
882
  }
883 884
}

885 886 887 888 889 890 891 892 893
size_t CodeMap::GetEstimatedMemoryUsage() const {
  size_t map_size = 0;
  for (const auto& pair : code_map_) {
    map_size += sizeof(pair.first) + sizeof(pair.second) +
                pair.second.entry->EstimatedSize();
  }
  return sizeof(*this) + map_size;
}

894
CpuProfilesCollection::CpuProfilesCollection(Isolate* isolate)
895 896 897 898 899 900
    : profiler_(nullptr),
      current_profiles_semaphore_(1),
      last_id_(0),
      isolate_(isolate) {
  USE(isolate_);
}
901

902 903 904 905 906
CpuProfilingResult CpuProfilesCollection::StartProfilingForTesting(
    ProfilerId id) {
  return StartProfiling(id);
}

907
CpuProfilingResult CpuProfilesCollection::StartProfiling(
908 909
    const char* title, CpuProfilingOptions options,
    std::unique_ptr<DiscardedSamplesDelegate> delegate) {
910 911 912 913 914 915
  return StartProfiling(++last_id_, title, options, std::move(delegate));
}

CpuProfilingResult CpuProfilesCollection::StartProfiling(
    ProfilerId id, const char* title, CpuProfilingOptions options,
    std::unique_ptr<DiscardedSamplesDelegate> delegate) {
916
  current_profiles_semaphore_.Wait();
917

918
  if (static_cast<int>(current_profiles_.size()) >= kMaxSimultaneousProfiles) {
919
    current_profiles_semaphore_.Signal();
920 921 922 923 924 925
    return {
        0,
        CpuProfilingStatus::kErrorTooManyProfilers,
    };
  }

926 927 928 929 930 931 932 933 934 935 936
  for (const std::unique_ptr<CpuProfile>& profile : current_profiles_) {
    if ((profile->title() != nullptr && title != nullptr &&
         strcmp(profile->title(), title) == 0) ||
        profile->id() == id) {
      // Ignore attempts to start profile with the same title or id
      current_profiles_semaphore_.Signal();
      // ... though return kAlreadyStarted to force it collect a sample.
      return {
          profile->id(),
          CpuProfilingStatus::kAlreadyStarted,
      };
937 938
    }
  }
939

940 941
  CpuProfile* profile =
      new CpuProfile(profiler_, id, title, options, std::move(delegate));
942
  current_profiles_.emplace_back(profile);
943
  current_profiles_semaphore_.Signal();
944 945 946 947 948

  return {
      profile->id(),
      CpuProfilingStatus::kStarted,
  };
949 950
}

951
CpuProfile* CpuProfilesCollection::StopProfiling(ProfilerId id) {
952
  current_profiles_semaphore_.Wait();
953
  CpuProfile* profile = nullptr;
954

955 956 957
  auto it = std::find_if(
      current_profiles_.rbegin(), current_profiles_.rend(),
      [=](const std::unique_ptr<CpuProfile>& p) { return id == p->id(); });
958 959 960 961 962 963 964

  if (it != current_profiles_.rend()) {
    (*it)->FinishProfile();
    profile = it->get();
    finished_profiles_.push_back(std::move(*it));
    // Convert reverse iterator to matching forward iterator.
    current_profiles_.erase(--(it.base()));
965
  }
966
  current_profiles_semaphore_.Signal();
967
  return profile;
968 969
}

970
CpuProfile* CpuProfilesCollection::Lookup(const char* title) {
971 972
  // Called from VM thread, and only it can mutate the list,
  // so no locking is needed here.
973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990
  DCHECK_EQ(ThreadId::Current(), isolate_->thread_id());
  if (title == nullptr) {
    return nullptr;
  }
  // http://crbug/51594, edge case console.profile may provide an empty title
  // and must not crash
  const bool empty_title = title[0] == '\0';
  auto it = std::find_if(
      current_profiles_.rbegin(), current_profiles_.rend(),
      [&](const std::unique_ptr<CpuProfile>& p) {
        return (empty_title ||
                (p->title() != nullptr && strcmp(p->title(), title) == 0));
      });
  if (it != current_profiles_.rend()) {
    return it->get();
  }

  return nullptr;
991 992
}

993 994 995 996 997 998 999
bool CpuProfilesCollection::IsLastProfileLeft(ProfilerId id) {
  // Called from VM thread, and only it can mutate the list,
  // so no locking is needed here.
  DCHECK_EQ(ThreadId::Current(), isolate_->thread_id());
  if (current_profiles_.size() != 1) return false;
  return id == current_profiles_[0]->id();
}
1000

1001 1002
void CpuProfilesCollection::RemoveProfile(CpuProfile* profile) {
  // Called from VM thread for a completed profile.
1003
  DCHECK_EQ(ThreadId::Current(), isolate_->thread_id());
1004
  auto pos =
1005 1006 1007 1008
      std::find_if(finished_profiles_.begin(), finished_profiles_.end(),
                   [&](const std::unique_ptr<CpuProfile>& finished_profile) {
                     return finished_profile.get() == profile;
                   });
1009 1010
  DCHECK(pos != finished_profiles_.end());
  finished_profiles_.erase(pos);
1011 1012
}

1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042
namespace {

int64_t GreatestCommonDivisor(int64_t a, int64_t b) {
  return b ? GreatestCommonDivisor(b, a % b) : a;
}

}  // namespace

base::TimeDelta CpuProfilesCollection::GetCommonSamplingInterval() const {
  DCHECK(profiler_);

  int64_t base_sampling_interval_us =
      profiler_->sampling_interval().InMicroseconds();
  if (base_sampling_interval_us == 0) return base::TimeDelta();

  int64_t interval_us = 0;
  for (const auto& profile : current_profiles_) {
    // Snap the profile's requested sampling interval to the next multiple of
    // the base sampling interval.
    int64_t profile_interval_us =
        std::max<int64_t>(
            (profile->sampling_interval_us() + base_sampling_interval_us - 1) /
                base_sampling_interval_us,
            1) *
        base_sampling_interval_us;
    interval_us = GreatestCommonDivisor(interval_us, profile_interval_us);
  }
  return base::TimeDelta::FromMicroseconds(interval_us);
}

1043
void CpuProfilesCollection::AddPathToCurrentProfiles(
1044
    base::TimeTicks timestamp, const ProfileStackTrace& path, int src_line,
1045 1046 1047
    bool update_stats, base::TimeDelta sampling_interval, StateTag state,
    EmbedderStateTag embedder_state_tag, Address native_context_address,
    Address embedder_native_context_address) {
1048 1049 1050
  // As starting / stopping profiles is rare relatively to this
  // method, we don't bother minimizing the duration of lock holding,
  // e.g. copying contents of the list to a local vector.
1051
  current_profiles_semaphore_.Wait();
1052
  const ProfileStackTrace empty_path;
1053
  for (const std::unique_ptr<CpuProfile>& profile : current_profiles_) {
1054
    ContextFilter& context_filter = profile->context_filter();
1055
    // If the context filter check failed, omit the contents of the stack.
1056 1057 1058
    bool accepts_context = context_filter.Accept(native_context_address);
    bool accepts_embedder_context =
        context_filter.Accept(embedder_native_context_address);
1059 1060 1061 1062 1063 1064 1065

    // if FilterContext is set, do not propagate StateTag if not accepted.
    // GC is exception because native context address is guaranteed to be empty.
    DCHECK(state != StateTag::GC || native_context_address == kNullAddress);
    if (!accepts_context && state != StateTag::GC) {
      state = StateTag::IDLE;
    }
1066
    profile->AddPath(timestamp, accepts_context ? path : empty_path, src_line,
1067 1068 1069
                     update_stats, sampling_interval, state,
                     accepts_embedder_context ? embedder_state_tag
                                              : EmbedderStateTag::EMPTY);
1070 1071 1072 1073 1074 1075 1076 1077 1078
  }
  current_profiles_semaphore_.Signal();
}

void CpuProfilesCollection::UpdateNativeContextAddressForCurrentProfiles(
    Address from, Address to) {
  current_profiles_semaphore_.Wait();
  for (const std::unique_ptr<CpuProfile>& profile : current_profiles_) {
    profile->context_filter().OnMoveEvent(from, to);
1079
  }
1080
  current_profiles_semaphore_.Signal();
1081 1082
}

1083 1084
}  // namespace internal
}  // namespace v8